Handling Duplicated Data Records 

Use

In a request, DataSources can transfer several data records to the BW  for a key of non-time-dependent- texts or -master data. If data records are transferred to the BW more than once within a request, this could be due to the application. You should not see it as an error. The BW provides functions that can deal with such an ambiguity when handling double data records.

Here, the DataSource transfers the information about whether it has the potential to transfer double data records. This information is transferred to the scheduler when a new InfoPackage is created. In the scheduler, you have the option of determining how the system behaves with double data records.

Prerequisites

·        The DataSource transfers potential double data records.

·        and non-time-dependent texts and master records are principally involved here.

Functions

If the above pre-requisites are satisfied, the BW system places the DataSource Transfers Double Data Records indicator on the processing tab strip.

The indicator Ignore Double Data Records is also set in this case by default. In BW, the last data record of a request is updated for a particular key by default, when data records are transferred more than once. The remaining data records are ignored for this key in the same request.

To maintain consistency, ignoring double data records is only possible when the data is updated serially. Serial updating is when data is firstly updated into the PSA and subsequently, after being successfully written to the PSA, is updated to the InfoObject master data- or text-table. This update method was only previously possible for transaction data. You can also change the corresponding settings for master data and texts in the scheduler. If a DataSource transfers potential double data records or if you manually set the Ignore Double Data Records indicator, the PSA Only update is automatically selected in the scheduler.

If the Ignore Double Data Records indicator is not set, double data records will cause an error. The error message is displayed in the monitor.

Double data record recognition is connected with the characteristic key. It is therefore logical that the DataSource should provide all characteristic key fields. If this is not the case, for example when key fields were hidden from the extract structure, the system will notify you when the transfer rules are activated.

Activities

You can also determine how double data records within a request are handled in the scheduler, independently of whether the setting allowing these potential double data records to be delivered was made to the DataSource or not. This is useful when the setting was not made to the DataSource but when the system knows from other sources that double data records are in transfer ( when flat files are loaded for example). You can then manually set the Ignore Double Data Records indicator in the scheduler.